The present invention generally relates to a printing device for printing on printing paper a video image displayed on the screen of a television or the like and particularly to a video image printer which is suitable for preserving a video signal or a plurality of video signals to be printed.
A conventional video image printer is provided with a semiconductor frame memory, in which one frame of image a video signal can be instantly stored in the frame memory, for example, as disclosed by JP-A 56-64884. In the video image printer using such a frame memory, there have been such advantages that one scene of successive television pictures can be instantly (accurately in 1/30 or 1/25 sec) stored and that a picture can be reproduced with fidelity to a stored video signal without any skew. In such a video image printer, however, a number of random access memories (hereinafter, referred to as RAMs) have been required as the semiconductor storage elements in the frame memory and therefore the printer has become extremely expensive in manufacturing cost and large in size. Further, in the video image printer of the frame memory type using RAMs, there has been such a disadvantage that the stored video signal or information was extinguished when a power supply was turned off because the content of the RAMs were electrically and temporarily stored.
In the case where one scene of moving pictures such as television pictures or the like was printed onto printing paper, consideration has not been taken with respect to a possible state in which a desired picture to be printed next might be displayed in printing any preceding picture. That is, since a video signal of only one video image was recorded in a frame memory and printed while reading-out this recorded picture from the frame memory, another picture to be printed next could not be applied to the frame memory to be memorized therein in printing the first-memorized picture, otherwise it was necessary to extinguish the picture being printed to memorize the other picture to be printed next. Such problems as described above have not yet been solved.